where to find Disk brake dust shield/backing plate

[old Chevy guy]

Im upgrading the front spindles and disk brakes on my 71 c20 to the JB8 type off of a 78 c 30. The brakes and rotors are bigger and also I'm going for the different long centers so I can run Bud rims to match my duallys I'm running in the rear. The set up fit like it belonged there but the dust shields were shot. Having a hard time, cant find anything listed on any parts sites. Anybody know where to find some replacements? Hoping for new.